Collaborative Research: Elucidating the contributions of nonlinearities in musculotendon properties to enabling locomotion in unpredictable environments.

合作研究：阐明肌肉腱特性中的非线性对在不可预测的环境中实现运动的贡献。

• 批准号: 2128545
• 负责人: David Lin
• 金额: $ 53.92万
• 依托单位: Washington State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2128545&HistoricalAwards=false
• 关键词: Collaborative; Research; Elucidating; contributions; nonlinearities

For animals that locomote on uneven and diverse terrains, the ability to negotiate obstacles that can impede their forward progression and can cause instability is critical to survival. In many cases, the musculoskeletal system handles these obstacles by itself, independent of control by the nervous system, but the exact mechanisms by which this occurs are not thoroughly understood. The overall objective of this proposal is to elucidate how specific features within the musculoskeletal system achieve the appropriate locomotor behaviors without needing reflex interventions from the nervous system. To achieve this objective, the researchers will study bipedal hopping by kangaroo rats within the context of abrupt changes in slope that can disrupt forward velocity and/or cause unwanted rotational pitch of the body. Novel experiments using a specially designed rotational treadmill will make it possible to expose kangaroo rats to controlled perturbations that mimic ecologically relevant obstacles. The conceptual framework of the studies is that the components of the musculoskeletal system represent an embedded intelligence that can ease the computational burden of centralized controllers for complex dynamic systems. We advance this idea by investigating specific examples in which specialized properties link functional demands, conditional properties, and system state. Translation of the findings can solve long-standing challenges for robots moving stably over variable terrains. Furthermore, the project will involve local high school teachers, who will develop, test, implement, and assess teaching modules based upon the ongoing research to encourage pre-college students to appreciate how the study of basic biology and engineering applications are complementary. The objective of this project is to elucidate how nonlinearities within the musculoskeletal system express contextually appropriate system properties to achieve desired motor function without needing neural feedback. The approach is to study bipedal hopping by kangaroo rats with abrupt changes in slope that can disrupt forward velocity and/or cause unwanted pitch. More specifically, the research will examine how the actions of ankle extensors are coupled to the mechanics of the feet, and how this coupling is modulated by the nonlinear features of tendon. This coupling is hypothesized to provide the functional benefit of automatically making the foot compliant upon landing to mediate perturbations and then stiff at takeoff to enable propulsion. To test this hypothesis, the research team will use an integrated framework of in vivo, in situ, and in silico methods to obtain behavioral data, test mechanistic hypotheses, and manipulate component properties, respectively. A novel custom-designed rotational treadmill will make it possible to have controlled perturbations that mimic ecologically relevant obstacles. More generally, nonlinearities expressed by a system’s components can expand a system’s range of operating conditions and contexts. The findings will provide guidance for the design of nonlinearities, namely, their type and parameterization, so that the nonlinearities will be advantageous for achieving function while interacting with unpredictable environments. By collaborating with local high school teachers, the PIs will build a network of STEM teachers who will develop, test, implement, and assess teaching modules based upon the research. In addition, the project will provide interdisciplinary research training and mentoring for two graduate students and one postdoctoral fellow.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

对于在不平坦和多样化地形上生存的动物来说，克服可能阻碍其前进并可能导致不稳定的障碍的能力对于生存至关重要。在许多情况下，肌肉骨骼系统自己处理这些障碍，独立于神经系统的控制，但这种情况发生的确切机制尚未完全了解。本提案的总体目标是阐明肌肉骨骼系统内的特定功能如何在不需要神经系统反射干预的情况下实现适当的运动行为。为了实现这一目标，研究人员将研究袋鼠大鼠在坡度突然变化的情况下的双足跳跃，这种变化可能会破坏前进速度和/或导致身体不必要的旋转俯仰。使用特别设计的旋转跑步机的新实验将使袋鼠大鼠暴露于模拟生态相关障碍的受控扰动成为可能。这些研究的概念框架是，肌肉骨骼系统的组成部分代表了一种嵌入式智能，可以减轻复杂动态系统集中控制器的计算负担。我们推进这一想法，通过调查具体的例子中，专门的属性链接的功能需求，条件属性和系统状态。这些发现的转化可以解决机器人在可变地形上稳定移动的长期挑战。此外，该项目将涉及当地高中教师，他们将根据正在进行的研究开发，测试，实施和评估教学模块，以鼓励大学预科学生欣赏基础生物学和工程应用的研究是如何互补的。这个项目的目的是阐明肌肉骨骼系统内的非线性如何表达上下文适当的系统属性，以实现所需的运动功能，而不需要神经反馈。该方法是研究双足跳跃的袋鼠大鼠的坡度突然变化，可以破坏前进速度和/或导致不必要的间距。更具体地说，这项研究将研究踝关节伸肌的动作是如何耦合到脚的力学，以及这种耦合是如何由肌腱的非线性特征调制的。这种耦合被假设为提供在着陆时自动地使脚顺应以调解扰动并且然后在起飞时变硬以实现推进的功能益处。为了验证这一假设，研究小组将使用体内，原位和计算机方法的综合框架来获得行为数据，测试机制假设，并分别操纵组件特性。一种新颖的定制设计的旋转跑步机将有可能有控制的扰动，模仿生态相关的障碍。更一般地，由系统的组件表示的非线性可以扩展系统的操作条件和上下文的范围。研究结果将为非线性设计提供指导，即它们的类型和参数化，使非线性有利于实现功能，同时与不可预测的环境相互作用。通过与当地高中教师合作，PI将建立一个STEM教师网络，他们将根据研究开发，测试，实施和评估教学模块。此外，该项目将为两名研究生和一名博士后研究员提供跨学科的研究培训和指导。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。